(a) Field of the Invention
This invention relates to the method of attachment of the moisture barrier in a firefighter""s protective garment. More particularly, the present invention is concerned with a discrete moisture barrier that is attached to the thermal barrier or the outer shell, or both, by means of a slide fastener system.
(b) Description of Prior Art
A firefighter protective garment is usually a coat, a pant or one-piece coverall consisting of three or more functional layers of fire-resistant materials. The various layers are normally the following:
the outer shell which provides protection against puncture, cuts, abrasion, and heat,
the moisture barrierxe2x80x94consisting usually of a woven or non-woven substrate to which a fire resistant semi-permeable polymer is coated or laminatedxe2x80x94which provides resistance to penetration by liquids and blood-borne pathogens while facilitating the transmission of metabolic heat away from the body of the firefighter;
the thermal barrierxe2x80x94usually consisting of an insulating layer of batting or non-woven fabric quilted or laminated to a woven face cloth-which provides the bulk of the resistance to the transmission of heat from the external environment to the body of the firefighter.
A common configuration and orientation of these layers in a firefighter garment is as follows:
The outermost layer is the outer shell fabric. Moving inwards, the next functional layer is the moisture barrier, orientated with the substrate towards the outer shell and the polymer towards the inside. The next functional layer is the thermal barrier, orientated with the thicker and softer insulating layer facing the moisture barrier film and the face cloth towards the body of the firefighter.
An alternative configuration reverses the order of the thermal barrier and the moisture barrier such that the moisture barrier is the innermost layer. In this alternative configuration, the substrate of the moisture barrier is closest to the wearer of the garment and the moisture barrier polymer is facing outwards. Furthermore, the thermal barrier is positioned such that the batting or nonwoven thermal insulating layer is immediately adjacent to the moisture barrier polymer.
In both these orientations, it will be noted that the moisture barrier polymer is never directly exposed to the inner or outer environment of the garment. Furthermore, the moisture barrier polymer is normally cushioned and protected by the soft thermal insulation of the thermal barrier.
The polymer is normally less than 100 microns thick. Chemically, it is usually from the family of polytetrafluoroethylene (PTFE), polyurethane, polyamide, or polyimide, used either singly or in combination. It may be micro-porous, hydrophilic or both. Because of its chemical composition and because of its thinness, the moisture barrier polymer is very fragile. It can be easily damaged, or its performance impaired, by heat, hard or sharp objects, some common chemicals, and by soiling. It can even be damaged by the fingernails or jewelry of the operators who handle the moisture barrier during the assembly of the garment.
In order to prevent an inadvertent exposure of the moisture barrier to either the external or internal environment of the garment, or to prevent potentially damaging foreign material from coming into contact with the polymer, the moisture barrier is normally sewn to the thermal barrier along the entirety of their common periphery and is orientated such that the polymer is on the inside of the resulting sandwich. In most firefighter protective garments worn in North America, the thermal and moisture barriers are sewn together to form what is commonly called xe2x80x9cthe linerxe2x80x9d. The liner is usually attached to the outer shell fabric by means of snaps, slide fasteners, or hook-and-pile fastener tape. These means of attachment permit the removal of the liner from the garment, principally to facilitate laundry or repairs.
In some designs of garments, particularly those manufactured in Europe, the moisture barrier and thermal barrier are permanently sewn to the outer shell.
Irrespective of whether the liner is removable or permanently attached to the outer shell fabric, in no instances, is it possible to detach or re-attach the moisture barrier to the thermal barrier or the outer shell without removing the stitching and then sewing a new or repaired moisture barrier back into place.
The firefighter garment, including its moisture barrier, must pass the stringent performance requirements of various standards, for example NFPA 1971, CGSB 155.1-M88, EN 469, if the garment is to be certified compliant with those standards and judged suitable for its intended use. There is also a standard, NFPA 1851, which mandates periodic verification of the condition and performance of the garment and its various components. However, the habit of permanently sewing the moisture barrier to either the thermal barrier or the outer shell or both, precludes an easy and ready verification of the continuing ability of the moisture barrier to meet those performance requirements after the garment has been put into use.
Furthermore, it is known that the moisture barrier will most likely cease to perform the function for which it was designed, or be able to pass the tests to which is was certified, before other components of the garment exhibit a similar failure. For example, it is commonly stated that fire fighter turnout gear should have a useful life of at least four to five years. However, various data have indicated that in garments using moisture barriers with a non-PTFE polymer, and in use for less than four years, over 50% of the moisture barriers failed a 2-psi hydrostatic test.
If it is found that the moisture barrier has failed, it cannot be readily removed for repair or replacement. Therefore, if the moisture barrier is found to be leaking, one option is to replace the entire liner with a new one even though the thermal barrier component thereof is still performing adequately. This option is unnecessarily expensive. A second option is to send the entire liner or garment back to the manufacturer or to an agency skilled in the art, for the removal and repair or replacement of the moisture barrier. This option is expensive because of the transportation costs and the labor required to effect the replacement. It also greatly inconveniences the user because his garment cannot be used while the liner is out of service for moisture barrier repair or replacement.
U.S. Pat. No. 5,655,222 discloses a firefighter garment in which the moisture barrier is not permanently sewn to the thermal barrier for the entirety of their common periphery. Instead, at one or more locations on the said periphery, there are inspection ports, with hook-and-pile fastener strips holding the two components together to prevent the ingress of potentially damaging foreign material between the two. The inspection ports permit one to pull the moisture barrier out through these openingsxe2x80x94in a manner similar to turning a dishwashing glove inside outxe2x80x94for inspection of the polymer. The aim of the patent is to permit a visual inspection of the moisture barrier polymer; it does not facilitate the actual testing of the moisture barrier. Furthermore, it is obvious that this design is not intended to, nor could it allow for, the ready removal and replacement of the moisture barrier should it be found to be defective. As well, the very act of pulling the moisture barrier out through the relatively small inspection port may cause the polymer to be damaged by the fingernails or jewelry of the untrained person doing the inspection.
It is an object of the present invention to readily permit the removal of the moisture barrier for both inspection and testing, and for repair where necessary or possible.
It a further object of the present invention to reduce the risk of inadvertently damaging the moisture barrier polymer when the moisture barrier is removed for said inspection, testing or repair.
It is an object of the present invention to permit the easy re-attachment of the moisture barrierxe2x80x94whether a new one or the repaired onexe2x80x94to the garment.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be readily separated from or attached to the thermal barrier component.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be readily separated from or attached to the outer shell component.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein a moisture barrier that no longer has the desired performance characteristics can be readily removed and replaced with a new or repaired one.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier is joined to the thermal barrier or the outer shell along the major part of its periphery by means of a flame and heat resistant slide fastener.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier is joined to the thermal barrier or the outer shell along the major part of its periphery by means of a waterproof and flame and heat resistant slide fastener.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be easily removed to permit visual inspection of the entire surface area of the moisture barrier film.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be quickly and easily re-attached to the liner subsequent to a visual inspection.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be easily separated from the thermal barrier so as to permit a visual inspection of the entire surface area of the substrate side of the thermal barrier.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the thermal barrier can be quickly and easily re-attached to the liner subsequent to such an inspection.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be easily separated from the thermal barrier so as to permit hydrostatic testing from either the film or substrate side of the moisture barrier.
It is another object of the present invention to provide a liner for a firefighter coat or pant wherein the moisture barrier can be quickly and easily re-attached to the liner subsequent to such a hydrostatic testing.
The present invention relates to a firefighter garment comprising an outer shell, a moisture barrier and a thermal barrier, wherein fastening means are provided for removably attaching the moisture barrier to the outer shell, the thermal barrier, or both, and for readily removing the moisture barrier therefrom, and inspecting, testing, repairing or replacing same under conditions to prevent damage to the moisture barrier.
The fastening means may removably attach the moisture barrier to the outer shell only, or to the thermal barrier only, or to both the outer shell and the thermal barrier.
The fastening means preferably comprise a flame and heat resistant slide fastener, such as a heat resistant Zipper(copyright) or more preferably a waterproof and flame and heat resistant slide fastener. It may also comprise snaps or a hook-and-pile tape, or the like.
In accordance with a preferred embodiment, the slide fastener is provided along at least a major part of periphery of the moisture barrier and along corresponding parts of the periphery of the outer shell, thermal barrier or both.
The invention also relates to a method for constructing a firefighter garment which comprises providing an outer shell, a moisture barrier and a thermal barrier, tailoring the outer shell, moisture barrier and thermal barrier to a predetermined firefighter garment design, and assembling the outer shell, moisture barrier and thermal barrier into the above firefighter garment. According to the invention, the method comprises removably attaching the moisture barrier to either the outer shell or thermal barrier, or both, under conditions that the moisture barrier can readily be removed therefrom, and inspected, tested, repaired or replaced by a new one, and be attached again without damage thereto.